When the Chicago Marathon changed dates this year and landed on Oct. 24, the same day as Washington's Marine Corps Marathon, Chicago race director Carey Pinkowski good-naturedly kidded his Marine Corps counterpart Rick Nealis that the D.C. race would draw "only the leftovers."

Yet the Marine Corps Marathon reached its capacity of 16,000 runners on March 1, and since then organizers have been recommending that thousands of would-be entrants instead try Chicago, Richmond and other races.

"We've had a phenomenal response this year, and next year will be even worse," said Nealis, unable to suppress a smile at the prospect.

Already preparing for their 25th anniversary in 2000, the Marines have carefully fostered and improved political connections with the District's new mayoral administration. The Marine Corps Marathon, once considered little more than a municipal irritant, is now supported and defended by city officials against civic groups that complain about road closures and other logistical hassles.

"The mayor and his office are well aware of the positive financial impact the marathon brings to Washington," Nealis said.

The race has long been one of the largest marathons in the world. Last year, with 16,000 runners, it ranked fourth in the country. Still, for a military event initially conceived to promote goodwill to now go toe-to-toe against a for-profit behemoth like Chicago--and more than hold its own--is surprising.

"Marine Corps has always done a great job," said Pinkowski, whose race receives massive corporate backing. "They put on a technically sound race. Marine Corps is more of a community-type event, while ours is more of a commercial race. We promote our elite athletes, like Boston, New York and London."

Chicago, which last year had more than 17,000 finishers, is filling faster than last year and will again be larger than Marine Corps. The Marine Corps field is constrained by city permits based upon the staging areas at the start and finish at the Marine Corps War Memorial.

"If we ever move the start to the Mall, we could have virtually unlimited numbers," Nealis said. The proposed construction of an Air Force memorial at the Iwo Jima memorial site in Arlington could necessitate such a change. The notion of a silver anniversary mega-race on the order of Boston's 100th marathon also is being considered by the Marines.

Nealis attributes the Marine Corps Marathon's popularity to the second running boom, as well as the Marines' reputation for careful attention to the needs of first-time marathoners.

"We try to put on a good show for the average runner," Nealis said.

Johnson Ponders Options

Last year's Marine Corps winner, Weldon Johnson, 26, from Washington, has not decided whether he will defend his title. Johnson is attempting to qualify for the Olympic trials in May and needs to run 2 hours 22 minutes or faster by April 2. He won last year in 2:25:31, and ran 2:22:19 recently in Vermont. Johnson said he may run Chicago.

Women's winner Kimberly Markland, 35, an Air Force clinical laboratory officer stationed in Texas, will attend this year's marathon but will not race.